The way I reload, the crimping becomes self regulating. I crimp with a Lee Factory crimp die in a separate step. The crimp ultimately gets adjusted for the shortest cases because I examine each completed round for proper crimp and tweak the die adjustment for more crimp as needed. If a longer case gets to the crimp stage, the increase in effort needed on the press handle to fully extend the ram is felt and I stop the crimp stroke where it is.
I've had very few over crimped cases.
I don't think my system would work using the the third die to seat and crimp together.
George
PS: Even over crimped cartridges go bang; just might be a slightly higher pressure load. That's probably only going to be an issue for bullseye target competition.
